Hello All..

I have an 87 IROC Z28. Motor is still at the machine shop, but I'm trying to get everything else squared away. When she's all done I will have a Chevy 383ci , the HP will be approx 600-625, and the torque will be approx in the 500-550 range. I will be going with a 4.11 rear most likely.

My concern is which tranny to go with in terms of manufacturer/model, etc.. Most likely going with a 4spd, also considering a 5spd, no auto.

Any suggestions for something that is rated to handle that output?

Thanks everyone-

Lou

 

Your budget and intended use are really important.
At what RPM will the engine be operated mostly?

 

Truthfully im not sure where the RPMs will be.. if i wanna cruise around 65 mph i probably want them around 2000...the car is obviously gonna have a lot coming outta the hole... im guessing most of the time she will probably be driven between 3000 to 5000..

 

If you want a 2000 rpm cruise at 65 you can forget about a 4 speed with 4.11 rear gears. Your looking at either a TKO 600 or a t56. I have a TKO and personally its not worth the hassle of putting it in. Its still giving me problems here and there (noisy in neutral and it leaks a bit even with new sealant). I would go and get a t56 professionally built to handle that kind of power.

 

No problems with my TKO-600, shifts like butter and wants to be beaten...

sub... did you use anaerobic sealant on your leak?

 

Whole trans has been rebuilt and sealed with anaerobic sealant. If it wasnt for the noise in neutral and the leak id be fine with the trans but its one thing after the other with this thing. Its been nothing but a headache from the day i got it. Note to anyone thinking of a TKO.....DONT BUY USED!!!

 

If you want to beat on it, I'd find a M22 and go from there... i've had a few of them in big hp cars and I've never had a problem out of them... Just make sure you have someone go thru it before you put it in...

 

The muncie back in the day was a fantastic trans but the problem with them is that they are a 1:1 final drive. He is going to be running 4.11 gears and wants a reasonable highway RPM as well. You cant do that with a muncie unless the other person wants to fork over a couple of grand for a gear vendors over drive unit to bolt to the back of the muncie but at that point you might as well build a t56 or buy a new TKO.